The head of a group representing more than 2,000 charities has accused the government's chief adviser on the "big society" of using dangerous rhetoric that alienates the voluntary sector on which the idea depends.

Stephen Bubb, of the Association of Chief Executives of Voluntary Organisations (Acevo), is furious about comments by Lord Wei on a blog and in a House of Lords debate.

The peer launched an attack on the mindset of "big charity", arguing that some voluntary organisations were "overly competitive, bureaucratic and unresponsive". He said the issue was less about size but how the organisations made people feel.

Bubb hit back this weekend, saying Wei's comments betrayed a "lack of understanding" about the work of national charities. "I have written to the chief executives of 300 of our members and I have got a response: they do not like it either," he said. He has asked his members to provide evidence of innovations to defend the work of large charities.

Bubb added: "It is dangerous because big, national charities are core in achieving what the government wants on big society. It is odd attacking the people he should be relying on." He said national charities were providing vital support for vulnerable groups such as autistic children, blind people, the mentally ill and those with learning disabilities.

Their scale made them able to innovate, he said, citing the Royal National Institute of Blind People, which is producing a chip to help the visually impaired navigate television channels. He pointed to campaigns by charities such as the NSPCC and research carried out by Cancer Research UK.

Bubb warned that it would be terrible if the "big society" was really only about "smaller, compliant, biddable" organisations. He said it was worrying that Wei was the man advising the prime minister, David Cameron, on the "big society".

"If he is saying 'Beware big charity', then that is very dangerous."

A spokesman for the cabinet office said: "Lord Wei is a vocal supporter of the sector. In a speech praising charities he expressed his view that a small minority had become unresponsive to citizens. He did not relate this view to the size of a charity; that's completely misleading. Lord Wei believes there is a definite role for large charities, particularly as facilitators of innovation.

"The government recognises the innovative approaches of charities large and small which is why we want them to have a greater role in public services."

Ahead of the spending review ministers are under intense pressure to prove that they do indeed value such organisations. One question is whether they will guarantee funding to the Every Child a Chance Trust – which runs one-to-one tuition for pupils struggling with numeracy and literacy. Ministers have so far refused to guarantee that £6m a year will continue to be made available to train specialist teachers.